Gasket, block, or head

[AZmike]

I recently bought a 1986 Prelude Si (A20A3) and on the trip home I managed to get the engine close enough to overheating that I needed to stop four times. I found the coolant a nice rusty color with little copper colored particles floating around in it. Anyway, since then I have flushed the system with water several times and replaced the radiator. Once I was satisifed that everything seemed to be working well I went ahead and added some cooling system deposit remover, went for a drive, and let it sit as recommended.

The next time I stated it up several hours later I had a constant output of whitish smoke (I think it was white, it was getting dark). I let it run for a minute or two and it didn't seem to get any better. I realize that water from the cooling system is getting into the combustion chamber. I guess my deposit remover pulled loose the bit of leak-stop that was keeping the coolant out of the engine.

What I wanted to know is how likely replacing the head gasket is to fixing the problem? How often is a cracked head or block the cause of this problem? I've already run a rather thorough search and didn't turn anything up. I'm trying to figure out what supplies (like another head) to get before tackling the job this weekend. Any advice is appreciated. Sorry about the essay-length post.

[Jareds 89 LX-i]

Sounds like headgasket time! I doubt it's the block.... our cast iron blocks would have to get REALLY hot to make them warp or crack, but the aluminum heads warp/crack pretty easy if they get hot enough. If it overheated, the head would warp/crack WAY before the block would. But also it could be just the gasket itself, if the cooling system was neglected in the past and coolant never changed, antifreeze will become acidic and corrosive and eat right through the head gasket itself. Of course a compression test will tell you for sure if it's gone or not, but it sounds like it is the way you describe it.

If you replace it, you could just have the head shaved a bit, maybe a valve job while it's out, and a new gasket. That's what I did with mine, just took the head to a machine shop and they did everything real good. Slightly higher compression now too! If you have one of those places that just rebuilds heads though, like an exchange thing, that might be a little cheaper to just buy a rebuilt one.

[thegreatdane]

I was thinking... How would you go about checking if the block had any leaks? How would you find the leaks?

[NXRacer]

there is this powder that machine shops use to check for cracks. They put it in places where they think there's a crack and shine a UV light on it and the crack shows up like a sore thumb. I did it in auto shop class once way back in high school. I forget what the stuff is called though......

[Jareds 89 LX-i]

Originally posted by NXRacer
there is this powder that machine shops use to check for cracks. They put it in places where they think there's a crack and shine a UV light on it and the crack shows up like a sore thumb. I did it in auto shop class once way back in high school. I forget what the stuff is called though......

Magnaflux?